Hexidecimal (correctly spelled HEXADECIMAL; even more correctly termed, Sexadecimal)  HEX:
http://encyclopedia.thefreedictionary.com/Hexadecimal
In mathematics and computer science, hexadecimal, or simply hex, is a numeral system with a radix or base of 16 usually written using the symbols 0–9 and A–F or a–f.
For example, the decimal numeral 79 whose binary representation is 01001111 can be written as 4F in hexadecimal (4 = 0100, F = 1111).
DECIMAL  DEC:
http://encyclopedia.thefreedictionary.com/decimal
Decimal notation is the writing of numbers in the baseten numeral system, which uses various symbols for ten distinct quantities (0, 1, 2, 3, 4, 5, 6, 7, 8 and 9, called digits) to represent numbers. These digits are frequently used with a decimal point which indicates the start of a fractional part, and with one of the sign symbols + (plus) or − (minus) to indicate sign.
Discription (correctly spelled DESCRIPTION):
http://encyclopedia.thefreedictionary.com/description
A description consists of an enumeration of the quantitative and qualitative parameters which define something, that is, what something looks like, sounds like, feels like. A complete description includes useful subtle differences which can be useful for distinguishing one thing from another and general characteristics commonly noticed which in popular culture define something. Rigorous description is created and used in scientific disciplines as technical terminology.
Since someone mentioned it; OCTAL:
http://encyclopedia.thefreedictionary.com/octal
The octal numeral system is the base8 number system, and uses the digits 0 to 7.
OK, maybe I am being a smarty, but these are the definitions.
KCChiefs9690 is acurate in the application to scanners/communications:
Quote:
Originally Posted by KCChiefs9690
DEC= Decimal. This is the one that you program into your scanner.
HEX= Hexidecimal. This is NOT for scanners, it's used in programming motorola radios.
